Throttle control for internalcombustion engines



March 23, 1954 1 THOMAS 2,572,355

THROTTLE CONTROL {@611 INTERNAL-COMBUSTION ENGINES Filed June 19, 1951 s Sheets-Sheet 1 @i l l IN V EN TOR.

March 23, 1954 H. THOMAS 2,672,855

THROTTLE CONTROL FOR INTERNAL-COMBUSTION ENGINES Filed June 19, 1951 3 Sheets-Sheet 2 INVENTOR.

H. THOMAS March 23, 1954 THROTTLE CONTROL FOR INTERNAL-COMBUSTION ENGINES 5 Sheets-Sheet 3 Filed June 1 1951 INVENTOR.

Patented Mar. 23, 1954 OFFICE THROTTLE CONTROL FOR INTERNAL- COMBUSTION ENGINES Harry Thomas, Detroit, Mich.

Application June 19, 1951, Serial No. 233,810

Claims.

This invention relates to an improvement in throttle controls for internal-combustion engines and is particularly designed to increase engine efliciency, smoothness, power, and life. It is applicable to any engine installation but is especially adaptable to engines installed in vehicles.

In an internal-combustion engine, it is desirable to have the highest compression ratio possible in order to obtain maximum power and economy. The limiting factor is the roughness and tendency to detonate at wide open throttle, full-load operation. This roughness and detonation first becomes noticeable at low engine speeds; and as the compression ratio is increased, a pro portionately higher speed range is also affected.

This roughness and detonation may be reduced or eliminated by the use of the more expensive, uneconomical high-octane fuels. Retarding the ignition timing is also beneficial but is also uneconomical since it reduces the operating efficiency of the engine.

However, the more efficient and economical method of obtaining smooth and quiet performance is the one employed by the present invention, which is to limit the fiow of motive fluid entering the intake manifold of an internalcombustion engine to an amount which the engine can utilize without detonation or roughness.

One of the objects of the present invention is to provide an improved throttle control which permits the use of low octane fuels, higher compression ratios, and higher engine operating efficiencies than could be permitted with throttle controls used heretofore.

A secondobject is to provide means which will limit engine output at all speeds to any desirable fraction of maximum wide open throttle power. In this manner, both acceleration and maximum speed of a vehicle may be limited to any desirable extent and the life of the engine and vehicle considerably lengthened. Owners of large fleets of taxis, rental cars, trucks, etc., will find this feature of the inventionespecially useful in reducing maintenance and fuel costs.

Further and incidental objects and advantages of thepresent invention will appear in the following description, reference being had to the accompanying drawings.

Referring to the drawings,

Fig. 1 shows one embodiment of the form of the present invention.

Fig. 2 shows a novel throttle control principle which is employed in some of the forms of the present invention. Its usefuh'iess lies not only in the'fac't'that it furnishes a means of throttle 2 valve motivation without the necessity of link,- age, but also approximates the operation of the combination shown in Fig. 1 with the added advantage of greater simplicity.

Fig. 3 shows an embodiment of still another form of the present invention.

Referring back again to Fig. 1, an intake manifold or passage, I of an internal-combustion engine is shown with a throttle valve 2 cperated by the lever 3 with a spring 4 tending to close said throttle valve. The lever 3 is motivated by the throttle servo-motor 5 through a connecting rod 6. The throttle servo-motor 5 is motivated by sub-atmospheric pressures, the degree of motivation being proportional to the differential between the motivating pressure and atmospheric pressure. This motivating pressure is obtained from the intake manifold I at a point on the engine side of the throttle valve 2 and conducted to the throttle servo-motor 5 through the conduits 'I8-9. The motivating pressure is regulated by the metering valve I0 and governing valve II which are interposed in the conduit supply system I-8-9.

The metering valve II] is operated by the manually-controlled accelerator lever l2 through the connecting rod I3. A spring I4 returns the manually-controlled accelerator lever I2 and metering valve It to their so-called normal position in the absence of a manual motivating force. The metering valve I0 regulates the air flow through the atmospheric port I5 into the throttle servo-motor supply conduit 8 and air flow through conduit I in such a manner that at the normal, or closed throttle, position of the metering valve, atmospheric pressure is supplied to the throttle servo-motor rendering it inoperative, thus allowing the spring 4 to hold the throttle valve closed. As the metering valve is gradually moved to its fully-motivated position by the accelerator lever I2, the effect of the atmospheric port I5 gradually diminishes and the influence of the manifold pressure source increases and a gradually decreasing pressure is supplied to the throttle servo-motor 5, causing a proportional motivation of said servo-motor and consequently throttle valve 2.

A governing valve l I is installed between conduits 8-9 to further regulate pressure supplied to the throttle servo-motor 5. It accomplishes this by regulating air flow through a second atmospheric port It and also air flow through the conduit 3. A spring I? holds the governing valve I l in its so-called normal position in the absence of an opposing motivating force.

A governing servo-motor I8 connected tothe J) governing valve H by the connecting rod i9 is motivated by subatmospheric pressure obtained from the intake manifold l at a point on the engine side of the throttle valve 2 through the conduit 26. t a predetermined manifold pressure, as determined by the counterbalancing force of the spring [1, governing servo-motor it will pull the governing valve to its fully-motivated position. In this position, the governing valve relays pressure in the conduit 8 to the throttle servo-motor 5 without change. However, if the pressure in the intake manifold l approaches this predetermined value, the counterbalancing force of the resilient means I l is sufiicient tomove the governing valve to such a position that air is allowed to bleed into the supply conduit system, thereby increasing the pressure being delivered to the throttle servo-motor 5 and limiting throttle valve motivation sufficiently to prevent intake manifold pressure from exceeding the predeter- This method. does not have the precise control over maximum manifold pressure as does the methodlshown. in :Fig. 1. However, it approximates the performance of the latter and its advantagelies in its. greater simplicity. In the fully m'otivatedxposition of the metering valve it, the atmospheric port i5 is completely shut oil" and the-intakehmanifold pressure is relayed on to the throttle servo-motor 5 without change. Since the manifold pressure at-thevery low enginespeeds at Wide. open throttle isnearatmospheric, the .throt- L tleservoemotor does not havesufficient power to fully. open theithrottle valve but opensit only as far. .as its .power, which. diminishes inversely with the degree of throttle opening at any given speed, cancounterbalance the varying influence of the 4 resilient means 14. .As the enginespeed increases,

the manifold pressuredecreases which in turn increases the ability of. the .throttleservo-motor 5 to.;op.en:the throttle valve '2. In this manner, maximum output is permitted at .the higher speeds; while. atthe lower engine speeds a slight throttlingof the chargeentering the intake manifoldeifectively reduces engine output, thus resulting in. smoother performance withv higher compression ratios.

-Thendashpot. 22. prevents .too rapid opening of the; throttle valve, thusallowing suflicient time for the-pressure=actuated system to functionand prevent excessive: manifold pressures.

lndorder to vary the degree of throttling throughout thespeed'. range, an. adjustable stop meanswziisprovided on the metering valve II! which.alters. the fully=motivated position. of the metering alve -.t0..per mit anydesirableamount of air tocbleed into the atmospheric port [5. A manuallyroperated.adjustment-24 is also provided to vary the influence of-thev springs on throttle opening.

In. order to permit greater throttle valve openings to compensate for the loss of power caused by lower atmospheric pressures at higher altitudes, an atmospheric pressure responsive device @Sjis provided tovary the influence of the spring 4' inversely with altitude.

Fig., ashows another method, of controlling the throttle valve by using the governing valve H in combination with a manually controlled means. In this method, throttle servo-motor 5 serves as a throttle-limiting device in combination with the spring t and governing valve 1 l and has no power to open the throttle valve. It accomplishes the throttle valve limiting function by controlling the movable stop ,28. To open the throttle valve an additional ,connecting-lmember 29-between the manually-operated accelerator l2 and throttle valve 3 is provided. This connecting member 29 is constructed so as to be yieldable and resilient in :the'throttle-opening direction if opposed by a superior force from the combination of the throttle servomotor 5 and spring 4, but to act as a rigid member in the throttle-closing direction.

Thespring. treturns the manually-operated accelerator lever 52 and throttle valve 2 to their normal closed throttleff position in the absence of an opposing motivating force. The metering valve-ill and-related parts are omitted in this system.

An atmospheric pressure responsive element 2-5 is also-shown connected tothe spring l 'l insuch manner that :theinfluence of. the spring t! is weakened proportionately with. an increase in altitude, permitting fuller motivation of thethrottle valve 2-at higher altitudes.

-What I claim. is asfollows:

l. .In-an internal combustion enginehaving an intake manifold. and a throttle valve in said manifold controlling the fiow'of. motivating fluid into the engine, a throttle control comprising in combination: a pressure-actuated means connected'to said throttle .valveand motivated by subatrnospheric pressures :in a direction permitting throttle valve opening, a resilient means tending to close said throttle valve, a conduit supplying said pressure-actuatedmeans with intake manifold pressure obtained frornsaid manifoldat apoint on'thecngine side of said throttle valve, and an air bleed leading *intosaid conduit.

2. The throttle control as set forth in claim 1 including a valve controlling the flow of air through said .air bleed, a valve-control -means, and a manually-operated -means working in conjunction with said pressure-actuated and resilient means to control-the position ofsaid throttle valve.

3. The throttle control as setforth in claim 1 including a valve controlling the flow of air through said air bleed, a manually-operated means controlling the 'pcsition of saidmain valve, and a resilient means tending'to open said main valve.

4. The throttle control as set forth in claim 3 including a dashpot capable of slowing down the opening of said throttle valve While having little or no'efiect on the closing of said throttle valve.

5. Thethrottle control as set forth in claim 3 including a second valve interposed in said main conduit on-theintake manifold side of said main air bleed and operated concurrently with said. first valve but ina reverse manner, i. e., as said first valve closes said second valveopens.

6. The throttle control-as set-forth in claim 3 including an atmosphericpressure responsive adjustment means varying the-influence-of said resilient means on said throttle valve so as to permit greater throttle openings as" the atmospheric pressure decreases.

-.Tl. thr ttle co tro sset Q t -in claim 8 including ;;a manually-adjustable, .stop .means .to l mi the t nt o e-maca ed-valv cos-ms Th thr t Pniml F 1??? feriz Plhit l including a valve controlling the flow of air through said air bleed, a second pressure-actuated means controlling the position of said valve whereby said valve is moved toward the closed position as the motivating pressure decreases, a resilient means tending to open said valve, a conduit supplying said second pressure-actuated means with sub-atmospheric pressures obtained from said intake manifold at a point on the engine side of said throttle valve.

9. The throttle control as set forth in claim 3 including a second air bleed leading into said main conduit, a second valve controlling the flow of air through said second air bleed, a second pressure-actuated means controlling the position of said second valve whereby said second valve is moved toward the closed position as the motivating pressure decreases, a resilient means tending to open said valve, and a second conduit supplying said second pressure-actuated means with sub-atmospheric pressure obtained from said intake manifold at a point on the engine side of said throttle valve.

10. In an internal combustion engine having an intake manifold and a throttle valve in said manifold controlling the flow of motivating fluid into the engine, a throttle control comprising in combination: a manually-operated means controlling the position of said throttle valve in conjunction with other means, a resilient means tending to return said manually-operated means to the closed throttle position, a power transmitting connecting means between the manuallyoperated means and said throttle valve, one memher thereof being constructed to act as a rigid member when moving in the throttle closing direction but yieldable and resilient to a superior opposing force when moving in the throttle opening direction, a movable stop means limiting the degree of throttle valve opening, a main pressure-actuated means working in a throttle opening direction when supplied with sub-atmospheric pressures to vary the position of said stop means, a resilient means tending to move said stop means to the closed throttle position, a main conduit supplying said main pressure-actuated means with sub-atmospheric pressures from said intake manifold at a point on the engine side of said throttle valve, an air bleed leading into said conduit, a valve controlling the flow of air through said air bleed, a second pressure-actuated means controlling the position of said valve whereby said valve is moved toward the closed position as the motivating pressure decreases, a resilient means tending to open said valve, and a second conduit supplying said second pressureactuated means with sub-atmospheric pressures obtained from said intake manifold at a point on the engine side of said throttle valve.

HARRY THOMAS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,415,505 Mallory Feb. 11, 1947 2,529,437 Weinberger Nov. 7, 1950 

